Ribbon guide



March 26, 1957 J. w. HEIJNIS ET AL 2,786,674

RIBBON GUIDE 2 SheetsSheet 2 Filed Oct. 29, 1952 ATTURNEYS United States Patent "071cc RIBBON GUIDE James Watt Ijsbrand Heijnis and Chris'tiaan Engels, Arnhem, Netherlands, assignors, by mesne assignments, to American Enka Corporation, Enka, N. C., a corporation of Delaware Application October 29, 1952, Serial No. 317,466

Claims-priority, application Netherlands January 4, 1952 1 Claim. (Cl. 271-23) This invention relates to apparatus for manufacturing threads from thermoplastic material and, more particularly, to apparatus for use in a meltspinning process for the manufacture of such threads.

In one type of meltspinning process for the manufacture of threads from thermoplastic materials such as polyamides the solid material in the form of a ribbon is fed by a supply device such as a pump to a melting space and thence through a filter to spinnerets, the melting space, filter and spinnerets constituting the spinning head of the apparatus. From the spinnerets is extruded the material in the form of fine threads. The pressure re quired for extruding these threads is, in this first type of process, provided by the supply device for the ribbon. The ribbon is forced into the melting space by this supply device and as it melts it forces molten material already in the melting space through the filter and into the spinnerets. In such a system there is no Way of closely controlling the spinning head pressure and consequently no way of maintaining close control of thread denier. Therefore, such systems are usually used only for spinning fiber, the exact denier of which is not important.

Another type of meltspinning process designed to improve the control of thread denier employs a measuring pump between the spinning head and supply device. This measuring pump maintains constant spinning head pressure and consequently denier is substantially constant. The measuring pump may operate by recirculating enough of the molten material from the melting space to maintain a constant pump output of the material or may employ a slip clutch. In such a system the ribbon pressure, i. e., the pressure maintained by the ribbon against the molten material in the melting space, which pressure is due to the supply device for the ribbon, no longer so closely controls the spinning head pressure. Nevertheless, a satisfactory operation of this system is dependent upon the particular structure of the means used to guide the ribbon into the melting space. It is this particular structure to which this present invention is directed.

The guiding device has the function of leading the ribbon into the melting space of the spinning head. Difficulty usually arises in the conventional equipment when spinning-in or replacing the used up ribbon with a new ribbon. Since the guiding device should be spaced some distance from the inlet opening to the melting space, while spinning-in or replacing a ribbon it is extremely difficult to easily guide the ribbon into this inlet opening when nsin the conventional equipment. Generally speaking, the space between the guiding device and the inlet opening is necessary for two reasons. First, to prevent premature melting of the ribbon due to heat emanating from the melting space and second, so as to afiord easy access to the inlet opening to remove any extruded melt and incrustations therefrom.

It is, therefore, an object of this invention to provide a guiding device which afiords at the proper time the 2,786,674 Patented Mar. 26, 1957 correct spacing between said device and the inlet opening to the melting space of the spinning head while eliminating the problems above mentioned encountered during the spinning-in and replacement periods.

This and other objects will become apparent from the following detailed description of the accompanying drawings. 7

Figure 1 is a top plan view of the guide device constructed in accordance with this invention;

Figure 2 is a side elevation of the device of Figure 1;

Figure 3 is a fragmentary side elevation similar to Figure 2 but showing the attachment to the discharge end thereof of an auxiliary guide device constructed in accordance with this invention; and I Figure 4 is a perspective view of the auxiliary guide device constructed in accordance with this invention.

Referring to Figures 1 and 2 the plates 1 and 2 of the main guide device are arranged laterally spaced and parallel to each other. They are held in this position by bolt and nut assemblies 3, 4 and 5, 6. They are held in spaced relation by bushes mounted on the bolts. These plates have formed therein facing aligned grooves 8 and 9 which form the top and bottom guiding path for the ribbon 7. The ribbon 7 is advanced in these grooves by rollers 10 and 11 which are driven by any convenient means (not shown) which may, for instance, include a drive means employing a slip clutch (also not shown). Both plates 1 and 2 are provided with longitudinal openings 12 through which the progress of the ribbon through the guiding device may be observed. To facilitate threading of the ribbon 7 into the guide device the grooves are widened at 13 and 14, the widening 13 being located as shown adjacent the feed-in end of the plates and the widening 14 being located adjacent the lower or discharge end of the plates.

Referring now additionally to Figures 3 and 4 the ribbon 7 is fed in at the top or feed-in end of the plates and guided between these plates by grooves 8 and 9 to the discharge end, being advanced therein by rollers 10 and 11. The discharge end is located above the spinning head 29 and is spaced therefrom a distance of about 3 to 5 centimeters. To accommodate an auxiliary guide for this space the discharge end of the plates 1 and 2 is shaped in a particular manner. Each of them is cut to provide notches 18 and 19. By so cutting these plates, lugs 24 and 25 are defined. Each plate then has a pair of these lugs and preferably they are all aligned in a plane passing through the plates at substantially a right angle thereto. These lugs 24 and 25 receive the connecting portion of the auxiliary guide device 17 shown in Figure 4. The auxiliary guide device and the main guide device of Figures 1 and 2 constitute the complete guide device of this invention.

Turning to Figure 4 the auxiliary guide device 17 is provided with grooves 20 and 21 which are designed to receive the lugs 24 and 25 of the plates 1 and 2. The device 17 is also provided with a groove 22 for guiding the ribbon 7 therethrough. Additionally, the auxiliary guide device is provided with a heat insulated handle 23.

To connect the main guide device to the auxiliary guide device, the auxiliary guide device is manipulated into proper position manually, with the operator grasping the handle 23. The grooves 21 and 20 are engaged over the lugs 24 and 25 of both of the plates. By so doing the plate grooves 8 and 9 are aligned with the ribbon guide groove of the auxiliary guide device. The lower end 26 of the auxiliary guide device 17 is positioned over the widening 27 of the inlet opening 28 of the spinning head 29. The ribbon 7 is led through the grooves 7 and 8 and the groove 22 to the spinning head as shown particularly in Figure 3. When spinning-in is completed the auxiliary device 17 is removed. It must be remembered that this auxiliary guide device is used not only in spinning-in but in replacement of the old ribbon with a new ribbon. By observation through openings 12 of plates 1 and 2 it can be assured that the new ribbon begins its advance and the auxiliary device 17 is put into place as soon as the old ribbon is used up.

The device according to the invention can be applied to all thermoplastic materials which can be spun according to the ribbon meltspinning process. In all these cases it does not show any of the known difficulties, which often occur otherwise, such as bending of the spinning ribbon when being advanced, jamming and the irregular supply in general, heating of the supply device owing to heat conduction, and the phenomenon that the spinning ribbons get hot and consequently soften prematurely.

The inlet opening for the ribbon of this device can be easily cleaned if molten material has extruded and consequently crusts have formed.

The new device greatly facilitates the spinning-in, and the operation of exchanging the ribbons, which otherwise causes so many difficulties owing to the necessity to lay the ends of the refractory ribbons smoothly together for introducing them into the spinning head, is reduced to a few manipulations, as the ends of the spinning ribbons are already in alignment before they enter the spinning head.

What has been disclosed is the specific embodiment of the present invention. Other embodiments obvious from the teachings herein to those skilled in the art are contemplated to be within the spirit and scope of the following claim.

What is claimed is:

A ribbon guide device for guiding a ribbon in a meltspinning operation from a supply source, through a feeding station and to a spinning head, the improvement comprising a pair of laterally spaced parallel plates each of which has an entrance end and an exit end with a longitudinal opening disposed therebetween, transverse notches cut in the exit end of each of said plates thereby forming lugs, an auxiliary guide device having a ribbon guide groove and lug receiving slots therein, means for supporting one of said plates, means for securing the other of said plates to said supported plate while maintaining the pair in said spaced relationship, aligned grooves formed in the inner face of each of said plates and extending respectively from the longitudinal opening to the said entrance and exit ends whereby a channel is provided for the passage therethrough of said ribbon, said slots receiving said lugs to align said ribbon guide groove with the channel formed by said plates and means located in. the vicinity of the longitudinal openings and, rotating in a plane parallel to but between said, plates for propelling said ribbon through said guide device.

References Cited in the file of this patent UNITED STATES PATENTS 

